Wireless power transfer system with extended wireless charging range

Abstract

The present application relates to an apparatus which comprises a wireless power transfer system. This system comprises features which allow it to transfer more power wirelessly at extended distances than other systems operating in the same frequency range. The system possesses heat dissipation features; these features allow it to operate effectively in elevated-temperature environments, and to transfer power at higher levels and/or greater distances than a typical power-transfer system. The system also might include design features to withstand mechanical shocks, stresses, and impacts for use in a rugged environment. The system can also comprise adaptations to reduce electromagnetic interference, and can comprise specially shaped components with magnetic/ferrimagnetic properties that enhance performance. Other potential features include power conditioning by combining, within one circuit or one board, multiple elements that protect against excessive current, over-voltage, and/or reverse voltage.

The invention claimed is: 
     
       1. A power transmitter for wireless power transfer comprising:
 a transmitting coil assembly comprising:
 a magnetic backing comprising a top surface; 
 a magnetic ring affixed to the top surface of the magnetic backing, the magnetic ring comprising an outer wall; 
 a magnetic core affixed to the top surface of the magnetic backing and at least partially surrounded by the magnetic ring, wherein the magnetic backing extends beyond the magnetic core; and 
 a transmitting coil that surrounds the magnetic core, wherein the transmitting coil is configured to couple to a receiving coil of a wireless power receiver; 
 
 a printed circuit board having one or more transmitting electronics electrically connected to the transmitting coil; and 
 a shield comprising a first wall, a second wall, and a top surface, the shield positioned between the transmitting coil assembly and the printed circuit board, wherein at least a portion of the top surface of the shield extends radially outward from the magnetic backing, wherein the first wall and the second wall are both affixed to the top surface of the shield and both substantially surround at least a portion of the outer wall of the magnetic ring, wherein the first wall is separated from the outer wall of the magnetic ring by a first separation distance and the second wall is separated from the outer wall of the magnetic ring by a second separation distance, and wherein the second separation distance is larger than the first separation distance. 
 
     
     
       2. The power transmitter of  claim 1 , wherein the shield further comprises one or more notches. 
     
     
       3. The power transmitter of  claim 2 , wherein the one or more notches are positioned around one of a perimeter of the shield, within the shield, or combinations thereof. 
     
     
       4. The power transmitter of  claim 3 , wherein one or more connection ends of the transmitting coil are electrically connected to the one or more transmitting electronics of the printed circuit board through an opening between two ends of the magnetic ring, and wherein the opening of the magnetic ring and one of the one or more notches of the shield are aligned to permit the one or more connection ends of the transmitting coil to pass through and electrically connect to the one or more transmitting electronics of the printed circuit board. 
     
     
       5. The power transmitter of  claim 1 , wherein the first wall of the shield forms a portion of a first heat dissipater and the second wall of the of the shield forms a portion of a second heat dissipater. 
     
     
       6. The power transmitter of  claim 5 , wherein the shield is thermally connected to the one or more transmitting electronics and the shield is configured to dissipate heat generated by one or more of the transmitting coil, at least one of the one or more transmitting electronics, or any combinations thereof. 
     
     
       7. The power transmitter of  claim 1 , wherein the magnetic backing, the magnetic core, and the magnetic ring each comprise a ferrimagnetic material. 
     
     
       8. The power transmitter of  claim 1 , wherein the magnetic backing, the magnetic core, and the magnetic ring each comprise a magnetic shielding material. 
     
     
       9. The power transmitter of  claim 1 , wherein the transmitting coil assembly is configured to transfer wireless power with an operating frequency in a range from about 100 kilohertz (kHz) to about 300 kHz. 
     
     
       10. The power transmitter of  claim 1 , wherein the transmitting coil assembly is configured to transfer wireless power in a range from 5 Watts (W) to 30 W. 
     
     
       11. The power transmitter of  claim 1 , wherein the transmitting coil comprises a transmitting coil surface, and wherein a surface of the magnetic backing is equal to or greater than the transmitting coil surface. 
     
     
       12. The power transmitter of  claim 1 , wherein the magnetic core resides at an inner diameter of the transmitting coil, and wherein an inner surface of the transmitting coil and an outer surface of the magnetic core define a gap located therebetween. 
     
     
       13. The power transmitter of  claim 1 , wherein the magnetic backing, the magnetic core, and the magnetic ring each comprise a ferrite material that comprises a ferrite body, and wherein the ferrite body comprises a single, unitary constituent. 
     
     
       14. The power transmitter of  claim 1 , wherein the transmitting coil comprises one of a single coil, a multi-layer coil, a multi-tiered coil, or combinations thereof. 
     
     
       15. The power transmitter of  claim 1 , wherein one or more connection ends of the transmitting coil are electrically connected to one or more transmitting electronics through an opening between two ends of the magnetic ring. 
     
     
       16. A power transmitter for wireless power transfer comprising:
 a transmitting coil assembly comprising:
 a magnetic backing comprising a top surface; 
 a magnetic core affixed to the top surface of the magnetic backing, wherein the magnetic backing extends beyond the magnetic core; 
 a magnetic ring affixed to the top surface of the magnetic backing at an outer perimeter of the magnetic backing, the magnetic ring comprising an outer wall; and 
 a transmitting coil that surrounds the magnetic core, wherein the transmitting coil is configured to couple to a receiving coil; 
 
 a printed circuit board having one or more transmitting electronics electrically connected to the transmitting coil, wherein at least one of the one or more transmitting electronics comprises at least a control system loop that is configured to vary one or more of a frequency, an input voltage, an input current, or a duty cycle; and 
 a shield comprising a first wall, a second wall, and a top surface, the shield positioned between the transmitting coil assembly and the printed circuit board, wherein at least a portion of the top surface of the shield extends radially outward from the magnetic backing, wherein the first wall and the second wall are both affixed to the top surface of the shield and substantially surround at least a portion of the outer wall of the magnetic ring, wherein the first wall is separated from the outer wall of the magnetic ring by a first separation distance and the second wall is separated from the outer wall of the magnetic ring by a second separation distance, and wherein the second separation distance is larger than the first separation distance. 
 
     
     
       17. The power transmitter of  claim 16 , wherein the transmitting coil is configured to transfer wireless power at an operating frequency selected from a range of about 100 kilohertz (kHz) to about 300 kHz, a wireless power range selected from a wattage range of about 5 Watts (W) to about 30 W. 
     
     
       18. The power transmitter of  claim 16 , wherein the transmitting coil comprises a transmitting coil surface, and wherein a surface of the magnetic backing is equal to or greater than the transmitting coil surface. 
     
     
       19. The power transmitter of  claim 16 , wherein the first wall of the shield forms a portion of a first heat dissipater and the second wall of the of the shield forms a portion of a second heat dissipater, and wherein the shield is thermally connected to the one or more transmitting electronics and the first heat dissipater and the second heat dissipater of the shield are configured to dissipate heat generated by at least one or more of the transmitting coil, at least one of the one or more transmitting electronics, or any combinations thereof. 
     
     
       20. The power transmitter of  claim 16 , wherein the transmitting coil comprises one of a single coil, a multi-layer coil, a multi-tiered coil, or combinations thereof.